Mechanism of mitochondrial DNA-ROS-Drp1 axis in regulating phenotypic transformation of vascular smooth muscle cells
10.3760/cma.j.cn115354-20250826-00515
- VernacularTitle:mtDNA-ROS-Drp1轴调控血管平滑肌细胞表型转换的机制研究
- Author:
Chenqing LI
1
;
Yanyan HE
;
Yingkun HE
;
Bing ZHANG
;
Jia LIANG
;
Yao LIU
;
Chenming SI
;
Yang LIU
;
Yu WANG
;
Chi MA
;
Tianxiao LI
Author Information
1. 郑州大学人民医院（河南省人民医院）脑血管病科，郑州 450003
- Publication Type:Journal Article
- Keywords:
Mitochondrial DNA;
Reactive oxygen species;
Dynamin-related protein 1;
Vascular smooth muscle cell;
Phenotypic transformation;
Intracranial atherosclerotic
- From:
Chinese Journal of Neuromedicine
2025;24(10):997-1012
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the mechanism of mitochondrial DNA (mtDNA)-reactive oxygen species (ROS)-dynamin-related protein 1 (Drp1) axis in regulating phenotypic transformation of vascular smooth muscle cells (VSMCs).Methods:(1) VSMCs were divided into a control group, a synthetic VSMCs group, and a Drp1 siRNA+synthetic VSMCs group; cells in the Drp1 siRNA+synthetic VSMCs group were transfected with 50 nmol/L Drp1 siRNA for 48 h; cells in the latter two groups were treated with 20 ng/mL platelet-derived growth factor (PDGF)-BB, while cells in the control group were treated with an equal volume of solvent. After another 24 h of culture, Drp1 expression in VSMCs, and mitochondrial Drp1 and mitofusin 2 (Mfn2) expressions were detected by Western blotting, and changes in mitochondrial morphology were detected by mitochondrial fluorescent staining. (2) VSMCs were divided into a control group, a synthetic VSMCs group, and a mitochondrial fission inhibitor 1 (Mdivi-1)+synthetic VSMCs group; cells in the Mdivi-1+synthetic VSMCs group were pretreated with 50 μmol/L Mdivi-1 for 2 h; and cells in the latter two groups were treated with 20 ng/mL PDGF-BB, while cells in the control group were treated with an equal volume of solvent. After 24 hours of continued culture, expressions of α-smooth muscle actin (α-SMA), smooth muscle protein 22-α (SM22-α), proliferating cell nuclear antigen (PCNA), and Cyclin D1 were detected by Western blotting; invasion and migration abilities of VSMCs were detected by Transwell assay and scratch wound healing assay, respectively. (3) VSMCs were divided into a control group, a synthetic VSMCs group, and a N-acetylcysteine (NAC)+synthetic VSMCs group; cells in the NAC+synthetic VSMCs group were pretreated with 5 mmol/L NAC for 1 h; cells in the latter two groups were treated with 20 ng/mL PDGF-BB, while cells in the control group were treated with an equal volume of solvent. After 24 h of continued culture, expressions of Drp1, phosphorylated (p)-Drp1, α-SMA, SM22-α, PCNA, and Cyclin D1 were detected by Western blotting; changes in mitochondrial morphology were detected by mitochondrial fluorescent staining; intracellular ROS level was detected by 2', 7' -dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe; cell invasion and migration abilities were detected by Transwell assay and scratch wound healing assay, respectively. (4) VSMCs were divided into a control group, a synthetic VSMCs group, and a 5-Aza-2'-deoxycytidine (5-Aza-dC)+synthetic VSMCs group; cells in the 5-Aza-dC+synthetic VSMCs group were pretreated with 2 μmol/L 5-Aza-dC for 1 h; and then, cells in the latter two groups were treated with 20 ng/mL PDGF-BB, while cells in the control group were treated with an equal volume of solvent. After 24 h of continued culture, agarose gel electrophoresis was used to analyze the methylation degree in the mitochondrial D-loop region; intracellular ROS level was detected using DCFH-DA fluorescent probe; expressions of mitochondrial DNMT1, α-SMA, SM22-α, PCNA, and Cyclin D1 were detected by Western blotting; invasion and migration abilities were detected by Transwell assay and scratch wound healing assay, respectively.Results:(1) Compared with the control group and synthetic VSMCs group, the Drp1 siRNA+synthetic VSMCs group had significantly decreased Drp1 protein expression ( P<0.05). Compared with the control group, the synthetic VSMCs group had significantly increased Drp1 protein expression and decreased Mfn2 protein expression in the mitochondria ( P<0.05); compared with the synthetic VSMCs group, the Drp1 siRNA+synthetic VSMCs group had statistically decreased Drp1 protein expression and increased Mfn2 protein expression in the mitochondria ( P<0.05). Results of mitochondrial fluorescent staining showed that mitochondria in the control group were with filamentous structure, while mitochondrial fission in the synthetic VSMCs group was enhanced, and morphology of mitochondria in the Drp1 siRNA+synthetic VSMCs group tended to be continuous and complete. (2) Compared with the control group, the synthetic VSMCs group had statistically decreased α-SMA and SM22-α protein expressions and increased PCNA and Cyclin D1 protein expressions ( P<0.05). Compared with the synthetic VSMCs group, the Mdivi-1+synthetic VSMCs group had significantly increased α-SMA and SM22-α protein expressions and decreased PCNA and Cyclin D1 protein expressions ( P<0.05). Results of Transwell and scratch wound healing assays showed that compared with the control group, the synthetic VSMCs group had larger number of migrating cells and faster cell scratch healing; compared with the synthetic VSMCs group, the Mdivi-1+synthetic VSMCs group had smaller number of migrating cells and slower cell scratch healing. (3) Compared with the control group (1.10±0.02), the synthetic VSMCs group (1.53±0.02) had significantly increased p-Drp1 protein expression ( P<0.05). Compared with the synthetic VSMCs group, the NAC+synthetic VSMCs group (0.90±0.02) had statistically decreased p-Drp1 protein expression ( P<0.05). Results of mitochondrial fluorescent staining showed that mitochondria in cells of the control group were in a filamentous structure, while mitochondrial fission in cells of the synthetic VSMCs group was enhanced, and morphology of mitochondria in the NAC+synthetic VSMCs group tended to be continuous and complete. Results of DCFH-DA fluorescent probe showed that ROS level in the synthetic VSMCs group was higher than that in the control group, and ROS level in the NAC+synthetic VSMCs group was lower than that in the synthetic VSMCs group. Compared with the control group, the synthetic VSMCs group had significantly decreased α-SMA and SM22-α protein expressions and increased PCNA and Cyclin D1 protein expressions ( P<0.05). Compared with the synthetic VSMCs group, the NAC+synthetic VSMCs group had significantly increased α-SMA and SM22-α protein expressions and decreased PCNA and Cyclin D1 protein expressions ( P<0.05). Results of Transwell and scratch wound healing assays showed that compared with the control group, the synthetic VSMCs group had larger number of migrating cells and faster cell scratch healing; compared with the synthetic VSMCs group, the NAC+synthetic VSMCs group had smaller number of migrating cells and slower cell scratch healing. (4) Results of agarose gel electrophoresis showed that compared with the control group, the synthetic VSMCs group had significantly increased methylation rate in the mitochondrial D-loop region ( P<0.05); compared with the synthetic VSMCs group, the 5-Aza-dC+synthetic VSMCs group had statistically decreased methylation rate in the mitochondrial D-loop region ( P<0.05). Compared with the control group, the synthetic VSMCs group had statistically increased mitochondrial DNMT1 protein expression (1.03±0.03 vs. 0.55±0.03, P<0.05); and compared with the synthetic VSMCs group, the the 5-Aza-dC+synthetic VSMCs group (0.62±0.03) had significantly decreased mitochondrial DNMT1 protein expression ( P<0.05). Results of DCFH-DA fluorescent probe showed that ROS level in the synthetic VSMCs group was higher than that in the control group; ROS level in the 5-Aza-dC+synthetic VSMCs group was lower than that in the synthetic VSMCs group. Compared with the control group, the synthetic VSMCs group had significantly decreased α-SMA and SM22-α protein expressions and increased PCNA and Cyclin D1 protein expressions ( P<0.05). Compared with the synthetic VSMCs group, the 5-Aza-dC+synthetic VSMCs group had significantly increased α-SMA and SM22-α protein expressions and decreased PCNA and Cyclin D1 protein expressions ( P<0.05). Results of Transwell and scratch wound healing assays showed that compared with the control group, the synthetic VSMCs group had larger number of migrating cells and faster scratch healing. Compared with the synthetic VSMCs group, the 5-Aza-dC+synthetic VSMCs group had smaller number of migrating cells and slower scratch healing. Conclusion:The mtDNA-ROS-Drp1 axis may regulate the phenotypic transformation of VSMCs by modulating mitochondrial epigenetic modifications.
